Processing Complex Signals

Abstract

Much of the power of digital signal processing in communications equipment is the product of its the ability to form and manipulate complex signals. These complex signals often possess a frequency spectrum that is not realizable using real signals. A complex signal may have nonsymmetrical positive and negative frequency components, and this is often used to advantage. The concepts of complex signals are considerably different from those of real signals as we normally understand them. Therefore, it is necessary for students and engineers to study these concepts in detail if they are to take full advantage of the power of digital signal processing. This chapter discusses many of these concepts, and the reader is urged to take the time to obtain a thorough understanding of these basic ideas prior to proceeding with the rest of the material in the book.